IPSC 2016 题解(待续)

Problem A – Avoiding accidents

有几行注释掉是应付small的
不过我写的也太不优拉，大数据n那么小就是看不到

#include<bits/stdc++.h>using namespace std;#define For(i,n) for(int i=1;i<=n;i++)#define Fork(i,k,n) for(int i=k;i<=n;i++)#define Rep(i,n) for(int i=0;i<n;i++)#define ForD(i,n) for(int i=n;i;i--)#define ForkD(i,k,n) for(int i=n;i>=k;i--)#define RepD(i,n) for(int i=n;i>=0;i--)#define Forp(x) for(int p=Pre[x];p;p=Next[p])#define Forpiter(x) for(int &p=iter[x];p;p=Next[p])  #define Lson (o<<1)#define Rson ((o<<1)+1)#define MEM(a) memset(a,0,sizeof(a));#define MEMI(a) memset(a,127,sizeof(a));#define MEMi(a) memset(a,128,sizeof(a));#define INF (2139062143)#define F (100000007)#define pb push_back#define mp make_pair #define fi first#define se second#define vi vector<int> #define pi pair<int,int>#define SI(a) ((a).size())typedef long long ll;typedef unsigned long long ull;ll mul(ll a,ll b){return (a*b)%F;}ll add(ll a,ll b){return (a+b)%F;}ll sub(ll a,ll b){return (a-b+llabs(a-b)/F*F+F)%F;}void upd(ll &a,ll b){a=(a%F+b%F)%F;}int read(){    int x=0,f=1; char ch=getchar();    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}    return x*f;} string a[10];int p[10];int ca(int i,int j) {    if (a[i]==a[j]) return 4;    if (a[i].substr(1)==a[j].substr(0,3)) return 3;    if (a[i].substr(2)==a[j].substr(0,2)) return 2;    if (a[i].substr(3)==a[j].substr(0,1)) return 1;    return 0;} char s[1000],ans[1000];bool calc() {    int sz=0;    Rep(j,4) s[sz++]=a[p[0]][j];    For(i,9) {        int caa=4-ca(p[i-1],p[i]);        Fork(j,4-caa,3) {            s[sz++]=a[p[i]][j];        }    }    s[sz]=0;    if (sz<=39) {        cout<<s;//      cout<<strlen(s)<<endl;        For(i,39-sz) putchar('A');        puts("");        return 1;    }    return 0;}int main(){    freopen("A2.in","r",stdin);    freopen("a2.out","w",stdout);    int T=read();    while(T--) {        Rep(i,10) cin>>a[i];        Rep(i,10) p[i]=i;        do {            if (calc()) break;//          Rep(i,10) cout<<p[i]<<' ';cout<<endl;        }while(next_permutation(p,p+10));//      Rep(i,10) cout<<a[i];//      cout<<"AA"<<endl;    }    return 0;}

Problem C – Counting swaps

big cases 没跑出来
这题有一个小trick，一个环可以拆成2个。。
最讨厌算法错了

C small （C big 得挂机。。）

#include<bits/stdc++.h>using namespace std;#define For(i,n) for(int i=1;i<=n;i++)#define Fork(i,k,n) for(int i=k;i<=n;i++)#define Rep(i,n) for(int i=0;i<n;i++)#define ForD(i,n) for(int i=n;i;i--)#define ForkD(i,k,n) for(int i=n;i>=k;i--)#define RepD(i,n) for(int i=n;i>=0;i--)#define Forp(x) for(int p=Pre[x];p;p=Next[p])#define Forpiter(x) for(int &p=iter[x];p;p=Next[p])  #define Lson (o<<1)#define Rson ((o<<1)+1)#define MEM(a) memset(a,0,sizeof(a));#define MEMI(a) memset(a,127,sizeof(a));#define MEMi(a) memset(a,128,sizeof(a));#define INF (2139062143)#define F (1000000009)#define pb push_back#define mp make_pair #define fi first#define se second#define vi vector<int> #define pi pair<int,int>#define SI(a) ((a).size())typedef long long ll;typedef unsigned long long ull;ll mul(ll a,ll b){return (a*b)%F;}ll add(ll a,ll b){return (a+b)%F;}ll sub(ll a,ll b){return (a-b+llabs(a-b)/F*F+F)%F;}void upd(ll &a,ll b){a=(a%F+b%F)%F;}int read(){    int x=0,f=1; char ch=getchar();    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}    return x*f;} ll pow2(ll a,ll b,ll p)  //a^b mod p {      if (b==0) return 1%p;      if (b==1) return a%p;      ll c=pow2(a,b/2,p)%p;      c=c*c%p;      if (b&1) c=c*a%p;      return c%p;  }  ll inv(ll a){return pow2(a,F-2,F);}int a[100000+10]; bool b[100000+10];ll C(int n,int m) {    ll p=1;    For(i,m) p=mul(p,inv(i));    For(i,n-m) p=mul(p,inv(i));    For(i,n) p=mul(p,i);    return p;}#define MAXN (100000+10)ll f[MAXN];void calc() {    f[1]=1;    f[2]=1;    Fork(i,3,100000) {        f[i]=0;        For(j,i-1) {            ll p=mul(f[j],f[i-j]);            p=mul(p,C(i-2,j-1));            f[i]=add(f[i],mul(p,i));        }        f[i]=mul(f[i],inv(2));    }}ll fact(int n){    ll p=1;    if (n<=2) return 1;    Fork(i,3,n) p=mul(p,i);    return p;}ll dfs(vi ans) {}int main(){    freopen("C2.in","r",stdin);    freopen("c2.out","w",stdout);    int T = read();    calc();//  For(i,10) cout<<f[i]<<endl;    while(T--) {        int n=read();        For(i,n) {            cin>>a[i];        }        MEM(b)        vi ans;        ans.clear();        For(i,n) if (!b[i]) {            int p=i,len=0;            while(!b[p]) {                b[p]=1;                p=a[p];                ++len;            }            ans.pb(len);        }        sort(ans.begin(),ans.end());        ll an=1;        int sz=SI(ans),tot=n-sz;//      Rep(i,sz) cout<<ans[i]<<' ';cout<<endl;        Rep(i,sz) {            an=mul(an,f[ans[i]]);            an=mul(an,C(tot,ans[i]-1));            tot-=ans[i]-1;        }        cout<<an<<endl;    }    return 0;}

Problem D – Dumb clicking

js语言阅读理解+提交答案大模拟
感谢交会我js的xjtu

The game is a browser-based JavaScript application. You can either open it from the online problem statement, or open the file d/easy.html or d/hard.html from the downloadable archive. You’ll need a reasonably modern browser to play. Old versions of Internet Explorer probably won’t work.

由于我没时间研究big 的随机（自己弱）

small case

#include<bits/stdc++.h>using namespace std;#define For(i,n) for(int i=1;i<=n;i++)#define Fork(i,k,n) for(int i=k;i<=n;i++)#define Rep(i,n) for(int i=0;i<n;i++)#define ForD(i,n) for(int i=n;i;i--)#define ForkD(i,k,n) for(int i=n;i>=k;i--)#define RepD(i,n) for(int i=n;i>=0;i--)#define Forp(x) for(int p=Pre[x];p;p=Next[p])#define Forpiter(x) for(int &p=iter[x];p;p=Next[p])  #define Lson (o<<1)#define Rson ((o<<1)+1)#define MEM(a) memset(a,0,sizeof(a));#define MEMI(a) memset(a,127,sizeof(a));#define MEMi(a) memset(a,128,sizeof(a));#define INF (2139062143)#define F (100000007)#define pb push_back#define mp make_pair #define fi first#define se second#define vi vector<int> #define pi pair<int,int>#define SI(a) ((a).size())typedef long long ll;typedef unsigned long long ull;ll mul(ll a,ll b){return (a*b)%F;}ll add(ll a,ll b){return (a+b)%F;}ll sub(ll a,ll b){return (a-b+llabs(a-b)/F*F+F)%F;}void upd(ll &a,ll b){a=(a%F+b%F)%F;}int read(){    int x=0,f=1; char ch=getchar();    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}    return x*f;} int x[12],y[12];string rf[12]={"red s","green s","blue s","yellow s","orange s","pink s","red w","green w","blue w","yellow w","orange w","pink w"};int main(){    freopen("D.in","r",stdin);    freopen("d.out","w",stdout);    Rep(i,12) scanf("%d %d\n",&x[i],&y[i]);     char s[1000];    cout<<x[0]<<' '<<y[0]<<endl;    while(cin.getline(s,1000)) {        puts("next");        string S(s);        if (S.find("then")!=-1) {            Rep(i,12) {                if (S.find(rf[i])!=-1&&S.find(rf[i])<S.find("then")) cout<<x[i]<<' '<<y[i]<<endl;            }            Rep(i,12) {                if (S.find(rf[i])!=-1&&S.find(rf[i])>S.find("then")) cout<<x[i]<<' '<<y[i]<<endl;            }        }        else Rep(i,12) {            if (S.find(rf[i])!=-1) cout<<x[i]<<' '<<y[i]<<endl;        }    }    puts("done");    return 0;}

Problem G – Greatest number

给你一个只有加剪乘的表达式，任意删除字符使结果最大

贪心：你删得只剩数字就是最大
注意前导0，只有0的表达式

#include<bits/stdc++.h>using namespace std;#define For(i,n) for(int i=1;i<=n;i++)#define Fork(i,k,n) for(int i=k;i<=n;i++)#define Rep(i,n) for(int i=0;i<n;i++)#define ForD(i,n) for(int i=n;i;i--)#define ForkD(i,k,n) for(int i=n;i>=k;i--)#define RepD(i,n) for(int i=n;i>=0;i--)#define Forp(x) for(int p=Pre[x];p;p=Next[p])#define Forpiter(x) for(int &p=iter[x];p;p=Next[p])  #define Lson (o<<1)#define Rson ((o<<1)+1)#define MEM(a) memset(a,0,sizeof(a));#define MEMI(a) memset(a,127,sizeof(a));#define MEMi(a) memset(a,128,sizeof(a));#define INF (2139062143)#define F (100000007)#define pb push_back#define mp make_pair #define fi first#define se second#define vi vector<int> #define pi pair<int,int>#define SI(a) ((a).size())typedef long long ll;typedef unsigned long long ull;ll mul(ll a,ll b){return (a*b)%F;}ll add(ll a,ll b){return (a+b)%F;}ll sub(ll a,ll b){return (a-b+llabs(a-b)/F*F+F)%F;}void upd(ll &a,ll b){a=(a%F+b%F)%F;}int read(){    int x=0,f=1; char ch=getchar();    while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}    while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}    return x*f;} int main(){    freopen("G2.in","r",stdin);    freopen("g2.out","w",stdout);    int T=read();    while(T--) {        string s;        cin>>s;        int l=s.length();        bool flag=0;        Rep(i,l) {            if (s[i]=='0') {                if (flag) cout<<s[i];            }            else if (isdigit(s[i])) {                cout<<s[i];                flag=1;            }        }         if (!flag) puts("0");else        cout<<endl;    }    return 0;}